There has been known a solid oxide fuel cell (hereinafter may be referred to as “SOFC” or simply “fuel cell”) in which solid oxide is used as electrolyte. SOFC has a stack (fuel cell stack) formed by stacking a large number of fuel cells each including a plate-shaped solid electrolyte body and an anode and a cathode provided on opposite sides of the solid electrolyte body. A fuel gas and an oxidizing gas (e.g., oxygen within air) are supplied to the anode and the cathode, respectively, and are chemically reacted with each other via the solid electrolyte body, whereby electric power is generated.
Such a fuel cell includes a pair of inter connectors and a fuel cell main body (a laminate of a cathode, a solid electrolyte body, and an anode). A current collector is disposed for electrical connection between the fuel cell main body and the inter connector.
Another solid oxide fuel cell is disclosed (see Patent Document 1). In the disclosed solid oxide fuel cell, the current collector can be attached to at least one of the anode and the cathode, and depressions and projections which are engageable with depressions and projections of the current collector are formed on at least a portion of a surface of the electrode to which the current collector is attached. Also, a fuel cell in which a gas diffusion layer is disposed on the electrode surface of a membrane electrode assembly and a surface of the gas diffusion layer in contact with a gas flow path is roughened is disclosed (see Patent Document 2).